This invention relates to collective objects management systems in general, and in particular to an improved collective objects management system using R.F. object identification with multiple crystals.
The term “collective objects management systems” is a term coined to denote systems for generally keeping track of items (“objects”) in a collection of items. For example, an automobile parts warehouse at any given time has a collection of vehicle parts (“objects”) in inventory. The kind and number of such parts varies every day, as parts are sold and new parts are received. In order to keep track of the number and kind of vehicle parts in inventory, some type of collective vehicle parts management system must be used. Similarly, in a semiconductor manufacturing operation, at any given time there is a collection of integrated circuits (“objects”) of one or more types located somewhere in the facility, which must be accounted for using a collective integrated circuits management system. In supermarkets, a collection of a large number of different types of items, such as meats, produce, canned goods and the like is usually in inventory, with the number and types of objects varying widely on a daily basis and thus requiring a complex objects management system. In business offices and some homes, file storage cabinets are typically used to store documents used for both business and personal activities. A typical file storage cabinet has several pull-out drawers each containing a relatively large number of file folders (“objects”), with each folder containing one or more documents. In order to enable the documents contained in the various files to be readily accessed, some type of file management system is necessary.
In the case of file storage management, each file folder is typically provided with a tab portion visible when the file drawer is opened (usually along the upper edge of the folder) and containing readable information describing the content of the folder. The readable information is typically a short form of identification, such as an account name, a subject name (e.g., “Utilities Bills”) or the like.
In order to provide ready access to the individual documents contained in the folders, some type of indexing arrangement is normally used to identify the drawer location of each folder. A simple technique commonly employed is an alphabetical index card placed on the front panel of each drawer listing the file folders in alphabetical order. For example, one file drawer panel might have an index card listing files starting with the letters A-F, another drawer might have an index card listing files starting with the letters G-L, etc. Frequently, more sophisticated indexing arrangements are used, such as a computer-based index listing all files by a short form identifier and a corresponding enlarged and more thorough description of the file contents. Even such computer-based arrangements still require the use of a readable tab or tag on each file folder in order to identify a given folder to a user. This is highly undesirable, since it facilitates the search by any unauthorized user for a specific file name or for a file containing information of a particular type. Nevertheless, known file management systems require the use of visible tabs or tags in order for the files to be reasonably locatable.
In those applications in which several individuals have access to the file drawer contents, some arrangement is usually made to monitor the disposition of the files. For example, in a business application, it is convenient and sometimes necessary to provide a sign out and return procedure so that the whereabouts of a given file will always be known. Usually, such monitoring attempts fail to accurately track the files because of the failure of individuals to faithfully follow the procedure. Consequently, at any given time, the integrity of the file management system can only be verified by actually looking through each file drawer and checking the file folders and their contents with the master index. This requirement is both time-consuming and burdensome, and thus a severe disadvantage.
In known file management systems of the type described above, once a file folder is provided with a contents identifier, that folder is permanently associated with the nature of its contents. To change the contents to some other category, the folder must either be thrown away and a new, unmarked folder substituted in its place, or the identification label must be changed. In addition, the master index must be up-dated, either manually or by using the computer in a computer-based indexing system. These procedures are not always followed by office personnel, and the integrity of the file system is consequently compromised.
In all examples of known collective objects management systems, either the containers for the different objects or the objects themselves are usually provided with some type of human readable or machine readable identification indicia, such as a label or tag affixed to the object or the container. In more sophisticated systems, a computer is used to assist in keeping track of the objects. When an object is removed from the usual location, some procedure is typically used to note the fact that that object has been removed from its normal location. This is accomplished either by operator entry of the change into the system computer, or by using tag or label reading devices (e.g., bar code readers) to enter the information into the system computer.
U.S. Pat. No. 5,977,875 issued Nov. 2, 1999 for “Collective Objects Management System Using R.F. Object Identification”, the disclosure of which is hereby incorporated by reference, discloses a collective objects management system which eliminates the disadvantages noted above with file management systems. In addition, the collective objects management system disclosed in the '875 U.S. patent provides a simple and efficient way to find a desired object stored somewhere in a large collection of different objects. The system disclosed in the '875 U.S. patent uses R.F. sensitive circuits to maintain control of all objects in a collection. Each object has an associated R.F. sensitive circuit which resonates at a unique frequency when an R.F. signal at that unique frequency is received by the circuit, and an indicator coupled to the R.F. circuit for identifying the object to a human operator. The indicator is preferably a visible indicator—such as an LED—coupled to the object or the container for the object and which can readily be seen by a human operator. Alternatively, an audible indicator—such as a buzzer—can be used.
In a specific implementation of the invention in a file management system, a folder circuit is included in each file folder to be placed in a file drawer. Each folder circuit has a crystal responsive to a particular R.F. frequency, with the resonant frequency of a given crystal different from all the other crystals. Each folder circuit is electrically coupled to a drawer signal input/output using the electrically conductive upper support rails usually found in conventional file cabinets. One of the rails is modified by electrically isolating that rail from the remaining electrically conductive elements in the drawer.
Each folder circuit includes an indicator, preferably an LED visible indicator, mounted along the upper margin of the folder in a location visible to a user when the drawer is opened. In addition, each drawer is provided with an indicator, preferably a flashing LED visible indicator, mounted on the front panel of the drawer. A current detector circuit is used to control the state of the drawer panel indicator.
All drawer input/output terminals are electrically coupled in parallel to an associated computer, either using dedicated connectors (i.e., hard wired) or transceivers (i.e., wireless communication). The computer includes an R.F. signal generator capable of generating signals matching all the crystal frequencies. To find a file, a user specifies that file to the computer, typically by using a keyboard or a mouse. The computer causes the R.F. signal generator to generate an R.F. signal whose frequency matches that of the specified file. The R.F. signal is transmitted to all the file cabinets in the system, and thus to all the file drawers. If the specified file is located in any one of the drawers, the indicator on the front panel of the drawer containing that file folder, and the indicator of the correct file folder, are both activated. The user then opens the drawer with the active panel indicator and removes the file folder with the active file folder indicator.
As applied to a file management system, the collective objects management system disclosed in the '875 U.S. Patent eliminates the need for readable tabs or tags on each file folder, since the correct file folder is designated by the activated indicator. Also, the nature of a file folder can be changed by simply entering the necessary information into the computer. In addition, the integrity of the entire file system can be checked by using an R.F. sweep frequency generator to sweep the entire frequency range of crystal frequencies and detecting any frequency for which a resonant response is absent. The system can be readily and conveniently incorporated into existing file cabinets having the electrically conductive dual rail folder support mechanism. For other types of collective objects management systems, such as auto parts warehouses and integrated circuit manufacturing operations, the system can be implemented using standard object containers of known design.
As noted above, in the '875 system each object has an associated R.F. sensitive circuit having a single crystal which resonates at a unique frequency when an R.F. signal at that unique frequency is received by the circuit. This arrangement provides a unique one-to-one correspondence between an object and a given frequency. In a collective objects management system having a large number of objects, such as some file management systems have a large number of files, a correspondingly large number of crystals each having a resonant frequency different from all the other crystals is required. In order to guard against incorrect crystal activation it has been found useful to impose a minimum frequency separation between all crystals in the collection of crystals in the system. For example, in a system designed to operate over a frequency range of about 2 to about 20 mHz., a minimum crystal frequency separation of 1 kHz has been found to provide good results. The minimum frequency separation requirement, however, imposes an upper limit on the total number of crystals which can be used in the system, which places an upper limit on the total number of objects which can be accommodated by the system.